1. Field of the Invention
The present invention relates to an optical scanning device, which is applicable, for example, to an optical pickup for use in a bar code reader, an optical disk device and the like.
2. Description of the Related Art
A schematic diagram of a conventional optical scanning device applied to a bar code reader is shown in FIG. 9. In this optical scanning device, a laser beam L emitted from a light emitting unit 1 is directed via a first condenser lens 2 to a mirror 3, on which a light path of the laser beam L is converted so as to be directed to a bar code 4 which is an object of a laser irradiation. A reflected light from the bar code 4, after conversion of its light path again on the mirror 3, and via a second condenser lens 5, is received by a light receiving unit 6.
A drive rod 8a of a drive unit 8 comprising an electromagnet is firmly fixed to the mirror 3 for urging the mirror 3 to swing in directions of an arrow A in a predetermined cyclic motion around a fulcrum of a swing axis 7. Thereby, an emission of the laser beam L directed to this mirror 3 is used for scanning a whole area of the bar code 4, and the reflected light from the bar code 4 is received by the light receiving unit 6 for reading out information of the bar code 4.
However, in the conventional optical scanning device having the above-mentioned configuration, there needs to be some space secured between component parts, for example, between the light emitting unit 1 and the mirror 3, or between the mirror 3 and the light receiving unit 6, thereby limiting small-scaling of respective component parts necessary for compact-sizing of the device itself. In particular, in order to be able to receive efficiently a reflected light from the bar code 4, the second condenser lens 5 must be relatively large sized as shown in the drawing, thereby requiring a large space to be secured for installing such a large-sized condenser lens 5.
Recently, a field of application of the optical scanning device is expanding rapidly and in wide areas, however, in line with this trend, there is a growing demand for its lower power consumption, therefore, a further compactness of the device itself is strongly desired.
The present invention has been contemplated to solve the above-mentioned problem associated with the prior art and to provide a novel optical scanning device, which is capable of realizing a compact sizing, a lightweight and a lower power consumption.
In order to solve the above-mentioned problem, a novel optical scanning device according to the present invention is provided, which is comprised of: a movable member on which a light emitting unit for emitting a light and/or a light receiving unit for receiving a reflected light are mounted; a fixed member which supports the movable member swingably; and a drive unit which drives the movable member to swing so as to enable a laser beam scanning, wherein the above-mentioned light emitting unit and/or the above-mentioned light receiving unit are disposed on a same surface of the movable member, and along a swing axial line of the movable member with respect to the fixed member.
Namely, a compact design of the device is pursued by directly mounting the light emitting unit and the light receiving unit on the movable member. Further, improvement in efficiency of light reception by the light receiving unit is pursued by disposing the light emitting unit and the light receiving unit on the same surface of the movable member, and along the swing axial line of the movable member.
Further, in order to solve the above-mentioned problem, an optical scanning device according to the present invention is provided, which is characterized by comprising an optical path conversion surface which has a swing axis, and directs a light path of a beam from a light emitting unit to an object to be irradiated with the beam while swinging around the swing axis, and receives a reflected light from the object irradiated with the beam, wherein the light receiving unit for receiving the reflected light is mounted on the light path conversion surface.
As described heretofore, according to the optical scanning device of the present invention, there is accomplished the following advantages that a total size of the device can be reduced into a more compact size than a conventional device thereby providing an increased degree of flexibility for installing the device, and also contributing to a cost reduction of the device, a lightweight design, a low power consumption, and an improved performance of the device.
According to an aspect of the present invention, a novel swing mechanism having a simple structure for moving the movable member is obtained thereby contributing to a cost reduction of the device.
According to another aspect of the present invention, a swing mechanism having a swing axis for swinging a very small scaled optical scanning device can be formed simply using the semiconductor production processing technique thereby contributing greatly to a compact design of the device.
According to another aspect of the present invention, a novel swing mechanism for the movable member can be obtained simply without need of applying any special processing to the movable member.
According to further another aspect of the present invention, a compact and low power consumption drive mechanism applicable to each swing mechanism, having the above-mentioned structure can be obtained.
According to another aspect of the present invention, a compact design of the device is attained without need of securing a large space for installing a light receiving unit, and without lowering the efficiency of light reception.
According to an aspect of the invention as claimed in claim 7, a further improved efficiency in the light reception can be realized.